1. Field of the invention
The present invention relates to a pipe heater, and more particularly, to a heater for heating a pipe to a proper temperature.
2. Description of the Prior Art
Some warming or heating purpose heating apparatuses are provided with a pipe heater that heats a pipe, installed together with, for example, a chemical material coating or deposition installation or a semiconductor manufacturing installation, to a proper temperature so as to prevent by-product deposited on the inner wall of the pipe from being fixed.
FIG. 5 is a perspective view a conventional pipe heater, FIG. 6 is a sectional view taken along line C-C′ in FIG. 5, and FIG. 7 is a sectional view taken along line D-D′ in FIG. 6.
As illustrated in the drawings, the conventional pipe heater includes a tubular heat insulating layer 110 having a pair of separating surfaces 111a formed over the entire length thereof, an external cover 142 bonded to the outer surface of the heat insulating layer 110 to enclose the heat insulating layer 110, a heating layer 120 installed inside the heat insulating layer 110 and provided with a heating wire 121, an internal cover 141 installed inside the heating layer 120 to enclose the heating layer 120, a restraint part 145 bonded to the external cover 142, lead wires 132 electrically connected to the heating wire 121, and connectors 131 electrically connected to the lead wire 132.
The heat insulating layer 110 is formed of aramid felt.
The heat insulating layer 110 formed thereby suppresses heat generated from the heating wire 121 from being transferred to the external cover 142.
The external cover 142 is formed of an insulating material such as PTFE (polytetrafluoroethylene).
In addition to the heating wire 121, the heating layer 120 includes a heating wire support base 122 that supports the heating wire 121.
The heating wire 121 is formed of an insulation-coated nichrome wire.
The heating wire 121 formed thereby fixed to the heating wire support base 122 by a sewing thread 123 formed of a heat-resistant material such as silica.
The heating wire support base 122 is made of a glass fiber tape.
In the state where the heating layer 120 is installed, the heat generated from the heating wire 121 is transferred to an object to be heated, i.e. the pipe through the internal cover 141.
The temperature heated by the heating layer 120 is detected by a temperature sensor, and a temperature value detected by the temperature sensor is provided to a heater control unit (that performs an ON/OFF control on a heating voltage supplied to the heating wire) or a control unit of an apparatus (e.g., a semiconductor process apparatus).
The internal cover 141 is formed of an insulating material, such as PTFE (polytetrafluoroethylene).
The restraint part 145 may be attached to the external cover 142 using, for example, female and male Velcro tapes.
The heating wire 121 is electrically connected to an external power source through the lead wires 132 and the connectors 131.
However, the conventional pipe heater has a problem in that since the heat insulating layer 110 is formed of felt, it is structurally poor in heat insulating property and has a limit in improving the heat insulating property by increasing the thickness thereof.
Korean Patent No. 10-1439989 (registered on Sep. 3, 2014 and entitled “Pipe Heater and Electromagnetic Wave Shielding Apparatus for the Same”) discloses a technique related to the conventional pipe heater as described above.